package com.forumdemo.forum.interceptor;

import com.forumdemo.forum.config.AppConfig;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: ws
 * Date: 2023-10-21
 * Time: 16:11
 */

// 登录拦截器
@Component
public class LoginInterceptor implements HandlerInterceptor {

    @Value("${forum.login.url}")
    private String defaultURL;

    /**
     * 前置处理（对请求的预处理）
     * @param request
     * @param response
     * @param handler
     * @return true：继续 <br/> false：流程中断
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        // 获取session 对象
        HttpSession session = request.getSession(false);
        // 判断 session 是否有效
        if (session != null && session.getAttribute(AppConfig.USER_SESSION) != null) {
            // 用户已经登录，校验通过
            return true;
        }
        // 校验不通过，跳转到登录界面
//        response.sendRedirect("/sign-in.html");// 耦合性太强
        // 在配置文件中定义
        // 校验 URL 是否正确（有可能不带 /)
        if (!defaultURL.startsWith("/")) {
            defaultURL = "/" + defaultURL;
        }
        response.sendRedirect(defaultURL);
        // 中断流程
        return false;
    }
}
